The present invention relates to electro-optical connectors which are suitable for detachably interconnecting a pair of communications cables, each of which contains an optical and one or more electrical conductors. The invention relates particularly to such connectors which include cable terminal units for semi-permanently attaching to the cables.
In my U.S. Pat. No. 4,373,767, I have disclosed an underwater coaxial cable connector including a female connector unit containing a socket element enclosed in a dielectric fluid-filled chamber. The chamber has a novel seal through which the contact probe of a mating male connector unit is inserted. The seal is specifically designed to allow repeated cycling of the connector parts without loss of dielectric fluid or water leakage.
In my U.S. patent application Ser. No. 482,919 entitled "Underwater Connector", and filed on Apr. 7, 1983, I have further disclosed another underwater connector useful for interconnecting cables having electrical and optical conductors. The female part of the connector of my application includes a fluid-filled bladder having a penetrable seal which accommodates repeated insertion and withdrawal of an extended probe on a male connector unit without loss of fluid or water leakage.
In both cited references, a cable is terminated directly and semi-permanently with a connector unit. Terminating the cables with the connector halves in the field is virtually impossible, requiring the attendance of one or more skilled craftsmen and special equipment.
Moreover, optical conductors such as glass fibers are normally attached to a connector by non-reversible methods such as epoxying. Therefore, attachment of a connector unit to a cable carrying an optical fiber generally prevents the connector unit from being detached from the fiber without damage, and disables it from being reused with another cable. This can significantly increase installation and maintenance costs in a system comprising optical conductors. It also does not allow connectors to be used with more than one cable assembly, since they are not removable without damage. Attachment of an optical fiber to the connector is a painstaking and difficult task. In existing underwater optical connectors, the optical fibers are attached directly to the connector halves themselves. This places the entire connector in jeopardy in the event that the attachment is defective. Also, direct attachment does not allow testing the quality of the fiber junction until the connector is substantially assembled.
Therefore, there is an evident need for an underwater electro-optical connector which is reusable, interchangeable from cable to cable, does not unacceptably increase the difficulty of handling the cable to which it is attached, and is easily and reliably attached to an optical fiber.